Two-part piston ring



J. R. PETRIE.

TWO-PART PISTON RING.

APPLICATION FILED SEPT.28, 1921.-

1 426 766 I Patented Aug. 22, 1922;,

. INVENTOR WW. @i/fl M Ma 0 UNTTET) STATES PATIENT @FFTQE.

TWO-PART PISTON RING.

aaaegree.

Application filed September 28, 1921. Serial No. 503,944.

T 0 all whom it may concern Be it known that 1, JAMES R. PETRIE, a

citizen of the United States, and resident of the city and county of SanFrancisco, State of California, have invented new and usefulImprovements in Two Part Piston Rings, of which the following is aspecification.

My invention has for its object a piston ring particularly adapted topacking of the joint between the piston and cylinders of internalexplosion engines whereby a better joint for retaining the compressionand power stroke is attained and with a minimum of lubrication.

Other objects will appear from. the drawings and specifications whichfollow:

Referring to the drawings:

Fig. 1 is a cross section of one of my ring elements on the line 1-1 ofFig. 7.

Fig. 2 is a cross section of the second element on the line I-l of Fig.7.

Fig. 3 is a perspective view of one of the ends, and

Fig. 1 ma perspective view of the other end of the joint in the firstring element,

and adapted to dovetail with the end of Fig. 3.

Figs. 5 and '6 are the ends of the second ring element and adapted todovetail to form the j int therein.

Fig. 7 is'a plan view of'the assembled ring.

Figs. 8 and 9 show the ring in position in the engine piston andillustrate diagrammatically the movements and direction of force of therespective piston and cylinders.

Figs. 10 and 11 are front views of the joints of the two ring members.

Throughout the figures similar numerals refer to identical parts.

The ring of my invention consists of two parts or elements indicatedgenerally by the numerals 1 and 2 which are formed to interengagetogether forming a completed two-part ring of rectangular section asshown in Figs. 7, 8, 9. The member 1 is channeled at 3 to receive thetongue 4 of the L-shaped member 2. The surface 5 at such time lying uponthe surface 6. The member 2 is jointed as shown in Figs. 5, 6, whichends when brought together form a joint in the member 2 of the completedring as shown at 7 Fig. 7, and the ends of member Specification ofLetters Yatent. Patent gdl A 22 1922 1 as shown in Figs. 3 and a, whenbrought together are indicated in completed ring at 8 of F1g. 7. It willnow be seen that there is no openlng between the upper and lower part ofthe completed ring. The tongues 9, l0 co-operating with the passagewaysll,

12, respectively, and the continuous portion of the member 1 bridgingthe joint portion of the member 2 and the continuous portion of themember 2 bridgin the jointed portion of the member 1. if side view ofthe joint in the member 1 being shown in Fig. 10, and side view of thejoint of Fig. 2 being shown in Fig. 11. In these two figures the endsare separated but it is to be understood that when the ring is sprunginto place in its groove in the piston, these ends 13 and 14, 15 and 16,respectively, substantially abut against each other.

The operation is as follows: Referring particularly to Fig. 8, thepiston making a compression stroke in the direction of the arrow 25, thering seats against the bottom of the piston groove at 17, the'compressedgas passing freely through the slots 18 of the member 2 and thus againstthe surface thereof at 19 causes the ring member 2 to press against thecylinder wall 20 in the direction of the arrow 21, thus effecting asubstantial seal during the up stroke. On the down or power strokeopposite to the direction of the arrow 25 the action will be the samebecause of the compressed gases acting against the surfaee 19. Un thesuction stroke as shown in Fig. 9 the member 1 is held against the uppersurface 24 of the groove by the suction, or in other words by theexcessive atmospheric pressure in the direction of the arrow 22, so thatan efiective seal is provided for either direction of stroke and foreither direction of pressure. It is to be understood that the clearanceshown in these Figures 8 and 9 is much greater than in actual practicefor the purpose of facilitating the illustration.

I claim:

1. A two-part piston ring comprising an L-shaped part constructed andadapted to dovetail in to a second part, the two parts forming atwo-part ring of rectangular section, and each of said parts having ajoint consisting of ends formed to intermesh with each other and theparts assembled with the said joints opposite each other and grooves inthe outer surface of the L part in the assembled ring to pass pressurebetween the parts.

2. A two-part piston ring comprising an 5 L-shaped part constructed andadapted to dovetail in to a second part, the two parts forming atwo-part ring of rectangular section, and each of said parts having ajoint consisting of ends formed to intermesh with each other and theparts assembled with the said joints opposite each other and grooves inthe outer surface of the L part in the assembled ring to pass pressurebetween the parts, and the parts assembled with the said joints oppositeeach other.

JAMES R. PETRIE.

